mineral

Rough Quartz (Iron-stained)

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Milky white to tan/yellow (due to iron oxide staining); Luster: Vitreous to greasy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None/Conchoidal fracture; Specific gravity: 2.65

Hardness: 7 on Mohs scale
Color: Milky white to tan/yellow (due to iron oxide staining)
Luster: Vitreous to greasy

Identified March 22, 2026More mineral →

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Physical properties

Formation & geological history

Formed through hydrothermal processes or crystallization from cooling magma in igneous rocks like granite. Common in veins and pegmatites across all geological ages, primarily originating from silica-rich fluids.

Uses & applications

Used in glass manufacturing, electronics (due to piezoelectric properties), abrasives, and as a common gemstone for jewelry or decorative landscaping.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Pure quartz is clear, but impurities like iron create the yellowish tint seen in this specimen, often called 'limonite staining'.

Field identification & locations

Identify by its ability to scratch glass and lack of cleavage. Look for smooth, shell-like (conchoidal) fracture surfaces. Commonly found in riverbeds, mountains, and gravel pits worldwide.